This invention relates to an improved breadmaker and a bread making system capable of maintaining the freshness of the bread contained therein by monitoring and maintaining the ambient conditions such as temperature and humidity inside the baking chamber of the breadmaker.
Conventional breadmaker used at home generally has a baking chamber containing an electric heater at the bottom, a baking pan to be set inside the baking chamber for receiving ingredients therein, a stirrer for stirring and kneading the ingredients inside the baking pan and a stirring motor for rotating the stirrer in a specific manner.
In order to have a loaf of bread ready for morning consumption, the ingredients are usually prepared in advance and placed inside the baking pan overnight and subject to different steps of the breadmaking process such as stirring, kneading, leavening and baking. The entire breadmaking process usually takes several hours during the night to complete. After the breadmaking process is completed, the bread is usually left inside the baking chamber undisturbed until morning time. It may be several hours from the time the bread is ready to the time of consumption. During that time period, the bread will likely cool down. If the bread is reheated, it will harden due to the lost of moisture from evaporation, and thus affecting the taste and texture of the bread made.
For example, attempts have been made to reheat the bread in a microwave oven before consumption. However, this method is not preferred because of the extra step of removing the bread from the breadmaker and transferring it to a dish for microwave warming. In addition, even after reheating by microwave, the texture of the bread is still not satisfactory because the microwave warming process does not introduce any moisture back into the bread.
It is therefore an object of the present invention to provide an improved breadmaker generally of the type described above which, however, is capable of providing a controlled environment inside the baking chamber to keep the bread fresh for a period of time.
It is another object of the invention to provide an improved breadmaker capable of maintaining a desirable temperature, humidity, and aroma inside the baking chamber for a period of time.
It is still another object of the invention to provide an improved breadmaker capable of warming and maintaining the moisture inside the baking chamber to keep the bread contained herein warm and moist.
An improved breadmaker embodying the present invention, with which the above and other objects can be achieved, comprises a baking chamber having an electric heater at the bottom, a baking pan adapted to receive ingredients therein and be set inside the baking chamber, a stirrer for stirring and kneading the ingredients inside the baking pan and a stirring motor for rotating the stirrer in a specified manner.
The present invention also comprises ambient condition sensors for monitoring the ambient conditions inside the baking chamber. In the preferred embodiment, the ambient condition sensors comprises of a temperature sensor and a humidity sensor.
Furthermore, a humidifier and a surface heater are provided inside the baking chamber to provide sources of interior moisture and temperature. In addition, at least one vent hole is provided in the breadmaker to allow steam to escape from inside the baking chamber.
In a preferred embodiment, a controller is provided to control the humidifier and the surface heater in respond to the ambient condition sensors so that a controlled ambient environment can be maintained inside the baking chamber. The breadmaker according to the present invention is controlled by the controller to automatically carry out programmed sequence of operations used in different steps of the bread making process. The sequence of operations is stored in a storage in the controller, and can be either preprogrammed or manually inputted by the users. The preprogrammed or inputted parameters comprise: length of the keeping warm period after the baking is completed; temperature of the keeping warm period; time to wake up the breadmaker and to reheat the bread; inside humidity during the reheating period; temperature inside the baking chamber during the reheating period; and time to close off all the vent holes to prevent aroma and moisture from escaping from the baking chamber, etc.
Based on the programmed sequence of operations, the controller controls individual operation of the different components of the breadmaker (e.g. main heater, surface heater, humidifier, air circulating mechanism, vent holes and stirrer, etc) responding to the ambient condition sensors located inside the baking chamber. The controller determines the optimum combinations of the controlling parameters for the different components of the breadmaker during the kneading mode, baking mode, keeping warm mode, reheating mode and high heating mode, and thereby generates sets of control signals to control the various components of the breadmakers.
For example, during the kneading process, the controller first generates the appropriate control signals to control the electric heater and the stirrer motor to stir and knead the ingredients contained inside the baking chamber. Then, the controller generates control signals for suspending the operation of the stirrer motor to allow the ingredients to leaven.
In the baking mode, the controller turns on the electric heater to heat up the baking chamber for baking the dough contained therein. A controller with some of the above-mentioned features is disclosed in U.S. Pat. No. 5,704,277 issued to the same inventor of the present application, which is hereby incorporated by reference.
After the baking of the bread is completed, the present invention can keep the bread in preferably a warm temperature for later consumption (i.e. keeping warm mode). During the keeping warm mode, the controller turns on a surface heater along with a humidifier to maintain an predetermined warming temperature and humidity inside the baking chamber. After a predetermined period of time preprogrammed or entered by the user, the breadmaker will turn itself off automatically.
In the reheating mode, the breadmaker of the present invention can wake itself up at a selected time for reheating the bread. The breadmaker reheats the bread and reintroduces moisture back into the baking chamber so that the bread contained therein remains warm and moist.
In addition, in a preferred embodiment, the present invention provides a high heating mode. During the high heating mode, the main heater is turned on and the temperature inside the baking chamber is then raised to a sufficiently high temperature to drive off residual moisture and kill off any germs contained inside the baking chamber before the breadmaker is put away for storage.
Additional objects, features and advantages of various aspects of the present invention will become apparent from the following description of its preferred embodiments, which description should be taken in conjunction with the accompanying drawings.